Digital three-dimensional manufacturing, also known as digital additive manufacturing, is a process of making a three-dimensional solid object of virtually any shape from a digital model. Polyjet three-dimensional printing is an additive process in which curable liquid photopolymer drops are ejected from an ejector head to form successive layers of material on a substrate in different shapes to produce an object. Three-dimensional printing is distinguishable from traditional object-forming techniques, which mostly rely on the removal of material from a work piece by a subtractive process, such as cutting or drilling.
Some printers that produce three-dimensional objects use a flat staging area onto which one or more printheads positioned above the area eject drops downwardly to build layers of material and form an object in the area. The printhead is typically substantially smaller than the stage so either the printhead or the stage are moved in a process direction and cross-process direction, which are orthogonal to one another in the same plane. The printhead is moved multiple times to form each layer of the object. Additionally, one of the stage and the printhead are moved in a vertical direction relative to the plane of the process and cross-process direction plane to maintain an appropriate distance between the printhead and the object being built.
Currently, object printing is performed by positioning the printhead(s) above the platen and orienting the printhead(s) so they eject material drops downwardly towards the platen. In this manner, the object is built layer by layer with different materials being provided by different printheads. Because the object is built from the bottom up, outward projections require layers of support material to be built beneath the layer where the build material for the object is ejected. Additionally, object geometries can make the provision of low friction surfaces and the like on the sides of the object difficult to provide. Having a three-dimensional object printer that enables different orientations of material ejection would be useful.